Ash from incineration of cereal crop and oilseed rape straw can be used for soil fertilisation since it is a source of elements available to plants. At the Experimental Station in Mochełek (53o13’ N; 17o51’ E), owned by the UTP University of Science and Technology in Bydgoszcz, a pot experiment was performed to determine changes in the content of boron, copper, manganese, zinc and iron forms available to plants owing to the application of barley, wheat and rape straw ash at doses corresponding to 0.08-2.68 g∙kg-1. The pots were filled with loamy sandy soil. The paper provides evidence that the use of ash produced from incinerating straw of cereals and oilseed rape in soil fertilisation is a good way of ash waste management since such ash can be a valuable source of microelements essential for plants. Ash from barley, wheat, and oilseed rape straw can be used as fertiliser. Its application increases the soil pH values after application of a dose of 0.34 g∙kg-1 i.e. 1.0 Mg∙ha-1. Applied in the pot experiment, barley, wheat and oilseed rape straw ash at doses of 1.34-2.68 g∙kg-1 increased the richness of uncropped soil with forms of microelements available to plants by several to tens of per cent. Ash from straw of barley, wheat and oilseed rape affected similarly the chemical properties of soil. A higher content of microelements was observed in soil fertilised with ash from oilseed rape straw, as compared with the effects of barley straw ash application. Slight differences in the effects of the application of the tested types of ash to soil resulted from the differences in their chemical composition and different ash doses.

23.1.2018